At least in the main menu and in settings menu, mouse is noticeably lagging at times. Changing mouse sensitivity doesn't fix it. I can't yet explain what is causing it. So far didn't test it in the actual game.

Unfortunately we haven't run into this kind of problem in our office. You said that changing the mouse sensitivity does not help. Just to make sure, you should double check that you don't have any accelerator feature for your mouse turned on.

We have forwarded this issue to our QA, so we'll look into it if necessary. But sounds like the issue is fairly small, so I don't know if we should or can do anything about it.

My mouse is Logitech G400s with standard out of the box Linux support. It has hardware DPI adjusting buttons which are adjusting the mouse itself, not the system. I'll run some tests with other mouse, to see if it makes any difference.

I think I spoke too soon with this workaround. After I got my red graphics fixed, I tried to play the game and I got same problem that OP got, limited view angles. Only way to be able to change my camera angle more than the limited range was that I pressed ESC, moved my mouse cursor to other side of the screen, pressed ESC again to get back in game and then I could move my camera angle in new limited area. So I also had to revert the settings I mentioned earlier. Ah well.